Neutron Captureγ-Ray Spectra from the ElementsZ=17−30andZ=45−57

A NaI(Tl) scintillation counter and a 5819 photomultiplier have been used in conjunction with a very accurate and flexible twenty-channel pulse-height discriminator to study thermal neutron capture gammaray spectra. The energy range 20 kev-10 Mev was studied for the elements of atomic numbers 17-30 and 45-57 excluding the noble gases. In the case of chlorine, four lines are found below 2.1 Mev. These probably correspond to the first four excited states of ${\mathrm{Cl}}^{36}$. A neutron binding energy of 8.57±0.03 Mev is found for ${\mathrm{Cl}}^{36}$ by combining these lines with pair spectrometer data on the high energy lines. The method yields information on only the most prominent transitions in the capture gamma-decay schemes. No systematic distribution of these prominent lines is evident from the limited number of lines that can be resolved by this technique.